Dental chair



3 Sheets Sheet 2.

Patented Dec. 29., 1891.

D. STUCK. DENTAL CHAIR.

(No Model.)

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(No Model.) 3 Sheets-Sheet 3. D. STUCK.

DENTAL CHAIR.

No. 465,952. Patented Dec. 29, 1891.

E Q H 1 v I w u 2 J" n :infirm"? t u 0 flu m w:1: m i .F 0,0 m. I a MUNITED STATES PATENT OFFICE.

DElVELL STUCK, OF ROCHESTER, NEW YORK.

DENTAL CHAIR.

SPECIFICATION forming part of Letters Patent N 0. 465,952, datedDecember 29, 1891.

' Application filed February 5, 1891. $erial No. 380,336. (No model.)

To all whom it may concern:

Be it known that I, DEWELL STUCK, aresi dent of Rochester, in the countyof Monroe and State of New York, have invented certain new and usefulImprovements in Dental Chairs; and I do hereby declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it pertains to make and usethe same.

The object of the invention is to provide in a dental chair or the likemeans for controling and regulating the descent of the foot-rest when inan elevated position, which shall be easily operated from the back ofthe chair, and which shall maintain its operative relations whatever maybe the adjustment of the back; and it consists in the constructionhereinafter described and pointed out.

In the accompanying drawings, Figure l is a plan of the chair, partly insection, the upholstering being omitted and the outer part of thefoot-rest and the foot-roll or supplementary foot-rest broken away. Fig.2 is a longitudinal section on the line 00 w of Fig. 1, except that thefoot-rest lever for raising the foot-rest is not sectioned. Fig. 3 is alongitudinal section of the back on the line 'y 2 of Fig. 1. Fig. 4: isa plan, and Fig. 5 a section on line 2 a of Fig. 1, of a device forretarding the descent of the foot-rest. Fig. 6 is a transverse sectionof the pivoted bar connecting the seat-frame and the back on the line 1;o of Fig. 1, the view being from right to left. Fig. 7 is a similarsection on line to w of Fig. 1, the View being from left to right. Fig.Sis a top plan or end view of the back-frame, locking-lever, andoperating-button for the foot -rest-lowering mechanism. Fig. 9 is apartial section on linem m of Fig. 1, showing the inside of a foot-restbracket-guide provided with grooves, and also showing blocks movable insaid guides, the full lines indicating their lower and the dotted linestheir higher position, corresponding to the positions of the foot-restshown in full and dotted lines in Fig. 2 and Figs. 10 and 11 arerespectively end and side elevations of bearing-blocks for the foot-restto be inserted in grooves in the bracket-guides. Fig. 12 is a partialsection on line at n of Fig. 1.

The reference-letter a denotes the backframe, which is pivoted to theseat-frame n at j. The back-frame a is further connected with theseat-frame by a bar 6, pivoted to said latter frame at 2' and extendinginto a recess in the back-frame.

d is a clamping-block having an inclined face and movable in asimilarly-shaped recess 70, formed in the back-frame. The block isprovided with a screw-threaded opening, which receives the rod 0, whichis provided with an operating-handle b. The position of this handle(indicated by full lines in Figs. 1 and 8) corresponds to the positionof the parts when the clamp is operative. The screw-rod c, the foot ofwhich bears at h upon the bottom of the recess 10, having been suitablyturned, the block cl is thereby moved up in the recess and pushedlaterally against the bar 6, forcing it against the wall of the recessat m (see Fig. 7) by means of the inclination of the opposite wall ofsaid recess. To release the lock or clamp the handle I) is turned to theposition indicated by dotted lines in Fig. 8, which has the effect tolower clamping-block (Z and relieve the bar 6 of pressure from saidblock. By these devices the back can be adjusted to any desired positionand clamped therein.

f indicates a lug provided with a seat for a rubber cushion g, againstwhich bare strikes when the back is lowered to its lowest position, andis adapted to obviate jarring.

0 is a shoulder on 6, adapted to engage d when the back is elevated toits highest position.

Numeral 1 denotes the main foot-rest of a chair. At its rear upper andouter part, near the top of the upward extension 1", it is provided withpins or studs 11, and below, at the foot of said extension, it isprovided with like studs 8, all of which fit in blocks 12, (see Figs. 10and 11,) adapted to slide in grooves 9'and 10, (see Fig. 9,) formed inthe inside of brackets 13 pendent from the seat-frame. The studs 11 andits blocks are above and stud 8, with its blocks, are below the anglemade by the two parts 9 and. 10 of each groove. The rear of thefoot-rest is guided by the devices just described in such manner thatthe outer end of the rest is tilted toward the seat as it is raised andfrom the seat as it is lowered, as indicated in Fig. 2.

2 indicates a foot-lever for raising the rest.

It is connected to a rod or bar 2', which has hearings in boxes 3,secured underneath the foot-rest.

6 indicates a rod or bar supported in the brackets 13 and constituting afulcrum for the foot-lever. It also holds the brackets firmly in theirrelative position and supports the foot-rest-lowering mechanism. Thefootrest is raised by depressing the free end of foot-lever 2, the leversliding freely over its fulcrum and the studs 8 and 11, with theirbearing-blocks 12, sliding up in grooves 9 and 10, as indicated in Fig.2.

18 denotes a fiuid-column-retarding mechanism adapted to lower thefoot-rest. It has downward extensions 18, which embrace the rod 6, towhich they are fastened by a pin 17. The retarding device has twocompartments, as usual, in one of which is a piston 28, provided withpacking 29. At its footis an elastic disk 30, held in place by aserew31, these parts being of well-known form. The pistonrod 16 is pivoted at15 between offsetting lugs 20 on the foot-rest.

25 denotes a valve having a seat in the diaphragm 25.

26 is a spring adapted to hold the valve to its sea-t. This spring isconveniently coiled about a plug 27, passed through the end of thevalve-chamber. This chamber communicates at all times with thepiston-chamber. The valve-stem 23 has a bearin g in and passes freelythrough the offset 24, and is arranged in the path of the short arm of alever 14;, by which the valve may be opened. This lever is pivoted tothe hydraulic retarding device at 22, and is provided with an adjustablestop 21, which is so located as to strike the partition 18" of theretarding device when the short arm of lever 14 is depressed. By thisstop the extent of the movement of the lever and valve in one directionis determined.

It will be obvious that when the foot-rest is raised by the foot-lever,as before described, it will pull up the piston-rod l6 and piston 28,the retarding device being held down by its connection with rod 6. Theretarding device being supplied with oil or other liquid, it will bedrawn down into the valve-chamber by the action of the ascending piston,which also opens the valve and compresses its spring. The fluid thusintroduced under the elevated piston will sustain it and the foot-restuntil the valve is opened by the operation of lever 14.- to permit thefluid to escape from under the piston. The lever 14 is normally held outof contact with the valve-stem by the weight of its long arm.

32 is a cord or like connecting device adapted to raise the long arm oflever 14, and thereby open the valve to permit the descent of piston 28and of the foot-rest. This cord extends from the lever to thechair-back, passing, preferably, through the seat-frame and above thepivot and through a suitable hole in frame a. (See Figs. 6 and 7.)

34 is a pulley having an axis or pin 33, supported in brackets 39,secured by screws -10 in the back frame.

is a pulley, having axis 36 supported in a rod 37 at its foot. Cord 32passes around the pulleys, as indicated in Fig. 3, and has its upper endattached to bar 6 at 38.

37' is a push-button, and 41 a stop on the rod 37. The rod is normallyheld in the position indicated by full lines in Figs. 1 and 3 by lever11, the weight of whose long arm pulls the cord about the pulleys 34Land By pressing button 37 and depressing it to the position indicated indotted lines in Fig. 3 the long arm of lever 14. will be raised andvalve 25 opened, whereupon fluid can escape from under piston 28 and thefoot-rest descends. By this means the descent of the footrest can bevery nicely regulated by simply opening the valve more or less, asrequired, and without the use of t-hefoot or the exercise of anymaterial degree of strength and without the necessity of the operatorleaving the head of his patient or of so exerting himself as tointerfere with his proper work; and this easy and exact lowering of thefootrest can be effected by the means described, whatever be theposition of the adjustable back.

hen the back of the chair is turned on its pivotsj and raised, it ismoved along or off the bar 6, as indicated in dotted lines in Fig. 2. Asthe cord is attached to this bar, the back is also drawn off from it,and the guidepulleys are also moved along the cord, and thesemovementstake place without exerting any appreciable pull upon thevalve-lever.

It may be observed that the handle for clamping the bar 6 that connectsthe back and the seat-frame islocated near the button on the rod 37,whereby the clamp and the valve can be convenientiy manipulated atsuitable times to permit the desired lowering of the foot-rest and theadjustment of the back, which may be simultaneous or not, as desired.

Having thus described my invention, what I desire to secure by LettersPatent is- 1. In a dental chair, the combination, with the seat-frameprovided with suitable brackets, of a foot-rest, thefluid-column-retarding mechanism having its piston-cylinder sup portedfrom said brackets, a valve-chamber communicating with said cylinder, avalve normally closed, valve-operating devices extending to thechair-back, and the piston connected to the foot-rest, whereby thefoot-rest can be lowered by operating said devices extending to the backof the chair, and mechanism adapted to elevate the rest and the piston,substantially as set forth.

2. In a dental chair, the combination, with the seat-frame provided withsuitable brackets, of a foot-rest, the fiuid-column-retarding mechanismhaving its piston-cylinder supported from said brackets, a valve-chambercommunicating with said cylinder, valve-operating devices, and thepiston connected to the foot-rest, and mechanism adapted to elevate therest and the piston, and a flexible valve-operating connection extendingto the chair-back, substantially as set forth.

3. In a dental chair, the combination, with the seat-frame provided withsuitable brackets, of a foot-rest, the fluid-column-retarding mechanismhaving its piston-cylinder supported from said brackets, a valve-chambercommunicating with said cylinder, valve-operating devices, and thepiston connected to the f0ot-rest, and mechanism adapted to elevate therest and the piston, and a flexible valve operating connection extendingto a pivoted chair back frame and connected therewith, substantially asset forth.

4. In a dental chair, the combination of the seat-frame provided withbrackets 13, connected by rod 6, said brackets having bent grooves, thefluid-column-retarding mechan ism embracing a cylinder, piston, andvalvechamber pivotally connected to said rod, a foot-rest supported onsaid piston and 'provided with studs to enter the grooves, and mechanismfor raising the foot-rest, substantially as set forth.

5. In a dental chair, the combination,.with the seat-frame, of afoot-rest movably supported therein and provided with retardingmechanism, a cord or the like attached to and adapted for operating theretarding mechanism, a chair-back frame hinged to the chair-' frame, abar pivoted to the seat-frame, upon which said chair-back frame isadapted to be moved, said cord passing near the pivot of the bar andfastened to said bar, a rod supported-in the back-frame and adapted tomove said cord and operate the retarding mechanism, and guide-pulleys onthe chair-back and rod for the cord, whereby the back and the rest maybe raised or lowered independently, substantially as set forth.

6. In a dental chair, the combination of the seat-frame, the foot-restadj ustabl y supported from the frame, mechanism for retarding thedescent of said rest, and a cord or the like for operating the saidmechanism, extending therefrom through an opening in the chair seatframe and attached to a bar pivoted to the rear of the seat-frame, theopening for the cord being near the pivot of the bar, said pivoted barand the pivoted back-frame movable on the said bar and cord, whereby theback frame can be moved on its pivot without pulling the cord, andwhereby the retarding mechanism can be independently operated at willfrom the back of the chair, substantially as set forth.

7. In a dental chair, the chair-seat frame, the back-frame hinged tosaid seat-frame, the bar also hinged'to said seat-frame and extendinginto an opening in and concealed by the back-frame, the clamping-blockmovable in a recess within said back-frame, having an inclined wall,said block being adjacent to said bar, and the operating-rod adapted tomove the clamping-block along the inclined wall of the recess to clampthe bar against the back, all combined substantially as set forth.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

DEWELL STUCK.

Witnesses:

JAMES C. BAIRD, WILLIAM MAGUIRE.

